1/*-
2 * Copyright (c) 1999-2002 Poul-Henning Kamp
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/param.h>
31#include <sys/kernel.h>
32#include <sys/systm.h>
33#include <sys/bus.h>
34#include <sys/bio.h>
35#include <sys/lock.h>
36#include <sys/mutex.h>
37#include <sys/module.h>
38#include <sys/malloc.h>
39#include <sys/conf.h>
40#include <sys/vnode.h>
41#include <sys/queue.h>
42#include <sys/poll.h>
43#include <sys/sx.h>
44#include <sys/ctype.h>
45#include <sys/ucred.h>
46#include <sys/taskqueue.h>
47#include <machine/stdarg.h>
48
49#include <fs/devfs/devfs_int.h>
50#include <vm/vm.h>
51
52static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
53
54struct mtx devmtx;
55static void destroy_devl(struct cdev *dev);
56static int destroy_dev_sched_cbl(struct cdev *dev,
57    void (*cb)(void *), void *arg);
58static int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
59    int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
60    va_list ap);
61
62static struct cdev_priv_list cdevp_free_list =
63    TAILQ_HEAD_INITIALIZER(cdevp_free_list);
64static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
65    SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list);
66
67void
68dev_lock(void)
69{
70
71	mtx_lock(&devmtx);
72}
73
74/*
75 * Free all the memory collected while the cdev mutex was
76 * locked. Since devmtx is after the system map mutex, free() cannot
77 * be called immediately and is postponed until cdev mutex can be
78 * dropped.
79 */
80static void
81dev_unlock_and_free(void)
82{
83	struct cdev_priv_list cdp_free;
84	struct free_cdevsw csw_free;
85	struct cdev_priv *cdp;
86	struct cdevsw *csw;
87
88	mtx_assert(&devmtx, MA_OWNED);
89
90	/*
91	 * Make the local copy of the list heads while the dev_mtx is
92	 * held. Free it later.
93	 */
94	TAILQ_INIT(&cdp_free);
95	TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
96	csw_free = cdevsw_gt_post_list;
97	SLIST_INIT(&cdevsw_gt_post_list);
98
99	mtx_unlock(&devmtx);
100
101	while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
102		TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
103		devfs_free(&cdp->cdp_c);
104	}
105	while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
106		SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
107		free(csw, M_DEVT);
108	}
109}
110
111static void
112dev_free_devlocked(struct cdev *cdev)
113{
114	struct cdev_priv *cdp;
115
116	mtx_assert(&devmtx, MA_OWNED);
117	cdp = cdev2priv(cdev);
118	TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
119}
120
121static void
122cdevsw_free_devlocked(struct cdevsw *csw)
123{
124
125	mtx_assert(&devmtx, MA_OWNED);
126	SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
127}
128
129void
130dev_unlock(void)
131{
132
133	mtx_unlock(&devmtx);
134}
135
136void
137dev_ref(struct cdev *dev)
138{
139
140	mtx_assert(&devmtx, MA_NOTOWNED);
141	mtx_lock(&devmtx);
142	dev->si_refcount++;
143	mtx_unlock(&devmtx);
144}
145
146void
147dev_refl(struct cdev *dev)
148{
149
150	mtx_assert(&devmtx, MA_OWNED);
151	dev->si_refcount++;
152}
153
154void
155dev_rel(struct cdev *dev)
156{
157	int flag = 0;
158
159	mtx_assert(&devmtx, MA_NOTOWNED);
160	dev_lock();
161	dev->si_refcount--;
162	KASSERT(dev->si_refcount >= 0,
163	    ("dev_rel(%s) gave negative count", devtoname(dev)));
164#if 0
165	if (dev->si_usecount == 0 &&
166	    (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
167		;
168	else
169#endif
170	if (dev->si_devsw == NULL && dev->si_refcount == 0) {
171		LIST_REMOVE(dev, si_list);
172		flag = 1;
173	}
174	dev_unlock();
175	if (flag)
176		devfs_free(dev);
177}
178
179struct cdevsw *
180dev_refthread(struct cdev *dev, int *ref)
181{
182	struct cdevsw *csw;
183	struct cdev_priv *cdp;
184
185	mtx_assert(&devmtx, MA_NOTOWNED);
186	if ((dev->si_flags & SI_ETERNAL) != 0) {
187		*ref = 0;
188		return (dev->si_devsw);
189	}
190	dev_lock();
191	csw = dev->si_devsw;
192	if (csw != NULL) {
193		cdp = cdev2priv(dev);
194		if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
195			dev->si_threadcount++;
196		else
197			csw = NULL;
198	}
199	dev_unlock();
200	*ref = 1;
201	return (csw);
202}
203
204struct cdevsw *
205devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
206{
207	struct cdevsw *csw;
208	struct cdev_priv *cdp;
209	struct cdev *dev;
210
211	mtx_assert(&devmtx, MA_NOTOWNED);
212	if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
213		dev = vp->v_rdev;
214		if (dev == NULL)
215			return (NULL);
216		KASSERT((dev->si_flags & SI_ETERNAL) != 0,
217		    ("Not eternal cdev"));
218		*ref = 0;
219		csw = dev->si_devsw;
220		KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
221		*devp = dev;
222		return (csw);
223	}
224
225	csw = NULL;
226	dev_lock();
227	dev = vp->v_rdev;
228	if (dev == NULL) {
229		dev_unlock();
230		return (NULL);
231	}
232	cdp = cdev2priv(dev);
233	if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
234		csw = dev->si_devsw;
235		if (csw != NULL)
236			dev->si_threadcount++;
237	}
238	dev_unlock();
239	if (csw != NULL) {
240		*devp = dev;
241		*ref = 1;
242	}
243	return (csw);
244}
245
246void
247dev_relthread(struct cdev *dev, int ref)
248{
249
250	mtx_assert(&devmtx, MA_NOTOWNED);
251	if (!ref)
252		return;
253	dev_lock();
254	KASSERT(dev->si_threadcount > 0,
255	    ("%s threadcount is wrong", dev->si_name));
256	dev->si_threadcount--;
257	dev_unlock();
258}
259
260int
261nullop(void)
262{
263
264	return (0);
265}
266
267int
268eopnotsupp(void)
269{
270
271	return (EOPNOTSUPP);
272}
273
274static int
275enxio(void)
276{
277	return (ENXIO);
278}
279
280static int
281enodev(void)
282{
283	return (ENODEV);
284}
285
286/* Define a dead_cdevsw for use when devices leave unexpectedly. */
287
288#define dead_open	(d_open_t *)enxio
289#define dead_close	(d_close_t *)enxio
290#define dead_read	(d_read_t *)enxio
291#define dead_write	(d_write_t *)enxio
292#define dead_ioctl	(d_ioctl_t *)enxio
293#define dead_poll	(d_poll_t *)enodev
294#define dead_mmap	(d_mmap_t *)enodev
295
296static void
297dead_strategy(struct bio *bp)
298{
299
300	biofinish(bp, NULL, ENXIO);
301}
302
303#define dead_dump	(dumper_t *)enxio
304#define dead_kqfilter	(d_kqfilter_t *)enxio
305#define dead_mmap_single (d_mmap_single_t *)enodev
306
307static struct cdevsw dead_cdevsw = {
308	.d_version =	D_VERSION,
309	.d_open =	dead_open,
310	.d_close =	dead_close,
311	.d_read =	dead_read,
312	.d_write =	dead_write,
313	.d_ioctl =	dead_ioctl,
314	.d_poll =	dead_poll,
315	.d_mmap =	dead_mmap,
316	.d_strategy =	dead_strategy,
317	.d_name =	"dead",
318	.d_dump =	dead_dump,
319	.d_kqfilter =	dead_kqfilter,
320	.d_mmap_single = dead_mmap_single
321};
322
323/* Default methods if driver does not specify method */
324
325#define null_open	(d_open_t *)nullop
326#define null_close	(d_close_t *)nullop
327#define no_read		(d_read_t *)enodev
328#define no_write	(d_write_t *)enodev
329#define no_ioctl	(d_ioctl_t *)enodev
330#define no_mmap		(d_mmap_t *)enodev
331#define no_kqfilter	(d_kqfilter_t *)enodev
332#define no_mmap_single	(d_mmap_single_t *)enodev
333
334static void
335no_strategy(struct bio *bp)
336{
337
338	biofinish(bp, NULL, ENODEV);
339}
340
341static int
342no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
343{
344
345	return (poll_no_poll(events));
346}
347
348#define no_dump		(dumper_t *)enodev
349
350static int
351giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
352{
353	struct cdevsw *dsw;
354	int ref, retval;
355
356	dsw = dev_refthread(dev, &ref);
357	if (dsw == NULL)
358		return (ENXIO);
359	mtx_lock(&Giant);
360	retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
361	mtx_unlock(&Giant);
362	dev_relthread(dev, ref);
363	return (retval);
364}
365
366static int
367giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
368{
369	struct cdevsw *dsw;
370	int ref, retval;
371
372	dsw = dev_refthread(dev, &ref);
373	if (dsw == NULL)
374		return (ENXIO);
375	mtx_lock(&Giant);
376	retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
377	mtx_unlock(&Giant);
378	dev_relthread(dev, ref);
379	return (retval);
380}
381
382static int
383giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
384{
385	struct cdevsw *dsw;
386	int ref, retval;
387
388	dsw = dev_refthread(dev, &ref);
389	if (dsw == NULL)
390		return (ENXIO);
391	mtx_lock(&Giant);
392	retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
393	mtx_unlock(&Giant);
394	dev_relthread(dev, ref);
395	return (retval);
396}
397
398static void
399giant_strategy(struct bio *bp)
400{
401	struct cdevsw *dsw;
402	struct cdev *dev;
403	int ref;
404
405	dev = bp->bio_dev;
406	dsw = dev_refthread(dev, &ref);
407	if (dsw == NULL) {
408		biofinish(bp, NULL, ENXIO);
409		return;
410	}
411	mtx_lock(&Giant);
412	dsw->d_gianttrick->d_strategy(bp);
413	mtx_unlock(&Giant);
414	dev_relthread(dev, ref);
415}
416
417static int
418giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
419{
420	struct cdevsw *dsw;
421	int ref, retval;
422
423	dsw = dev_refthread(dev, &ref);
424	if (dsw == NULL)
425		return (ENXIO);
426	mtx_lock(&Giant);
427	retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
428	mtx_unlock(&Giant);
429	dev_relthread(dev, ref);
430	return (retval);
431}
432
433static int
434giant_read(struct cdev *dev, struct uio *uio, int ioflag)
435{
436	struct cdevsw *dsw;
437	int ref, retval;
438
439	dsw = dev_refthread(dev, &ref);
440	if (dsw == NULL)
441		return (ENXIO);
442	mtx_lock(&Giant);
443	retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
444	mtx_unlock(&Giant);
445	dev_relthread(dev, ref);
446	return (retval);
447}
448
449static int
450giant_write(struct cdev *dev, struct uio *uio, int ioflag)
451{
452	struct cdevsw *dsw;
453	int ref, retval;
454
455	dsw = dev_refthread(dev, &ref);
456	if (dsw == NULL)
457		return (ENXIO);
458	mtx_lock(&Giant);
459	retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
460	mtx_unlock(&Giant);
461	dev_relthread(dev, ref);
462	return (retval);
463}
464
465static int
466giant_poll(struct cdev *dev, int events, struct thread *td)
467{
468	struct cdevsw *dsw;
469	int ref, retval;
470
471	dsw = dev_refthread(dev, &ref);
472	if (dsw == NULL)
473		return (ENXIO);
474	mtx_lock(&Giant);
475	retval = dsw->d_gianttrick->d_poll(dev, events, td);
476	mtx_unlock(&Giant);
477	dev_relthread(dev, ref);
478	return (retval);
479}
480
481static int
482giant_kqfilter(struct cdev *dev, struct knote *kn)
483{
484	struct cdevsw *dsw;
485	int ref, retval;
486
487	dsw = dev_refthread(dev, &ref);
488	if (dsw == NULL)
489		return (ENXIO);
490	mtx_lock(&Giant);
491	retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
492	mtx_unlock(&Giant);
493	dev_relthread(dev, ref);
494	return (retval);
495}
496
497static int
498giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
499    vm_memattr_t *memattr)
500{
501	struct cdevsw *dsw;
502	int ref, retval;
503
504	dsw = dev_refthread(dev, &ref);
505	if (dsw == NULL)
506		return (ENXIO);
507	mtx_lock(&Giant);
508	retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
509	    memattr);
510	mtx_unlock(&Giant);
511	dev_relthread(dev, ref);
512	return (retval);
513}
514
515static int
516giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
517    vm_object_t *object, int nprot)
518{
519	struct cdevsw *dsw;
520	int ref, retval;
521
522	dsw = dev_refthread(dev, &ref);
523	if (dsw == NULL)
524		return (ENXIO);
525	mtx_lock(&Giant);
526	retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
527	    nprot);
528	mtx_unlock(&Giant);
529	dev_relthread(dev, ref);
530	return (retval);
531}
532
533static void
534notify(struct cdev *dev, const char *ev, int flags)
535{
536	static const char prefix[] = "cdev=";
537	char *data;
538	int namelen, mflags;
539
540	if (cold)
541		return;
542	mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
543	namelen = strlen(dev->si_name);
544	data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
545	if (data == NULL)
546		return;
547	memcpy(data, prefix, sizeof(prefix) - 1);
548	memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
549	devctl_notify_f("DEVFS", "CDEV", ev, data, mflags);
550	free(data, M_TEMP);
551}
552
553static void
554notify_create(struct cdev *dev, int flags)
555{
556
557	notify(dev, "CREATE", flags);
558}
559
560static void
561notify_destroy(struct cdev *dev)
562{
563
564	notify(dev, "DESTROY", MAKEDEV_WAITOK);
565}
566
567static struct cdev *
568newdev(struct cdevsw *csw, int unit, struct cdev *si)
569{
570	struct cdev *si2;
571
572	mtx_assert(&devmtx, MA_OWNED);
573	if (csw->d_flags & D_NEEDMINOR) {
574		/* We may want to return an existing device */
575		LIST_FOREACH(si2, &csw->d_devs, si_list) {
576			if (dev2unit(si2) == unit) {
577				dev_free_devlocked(si);
578				return (si2);
579			}
580		}
581	}
582	si->si_drv0 = unit;
583	si->si_devsw = csw;
584	LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
585	return (si);
586}
587
588static void
589fini_cdevsw(struct cdevsw *devsw)
590{
591	struct cdevsw *gt;
592
593	if (devsw->d_gianttrick != NULL) {
594		gt = devsw->d_gianttrick;
595		memcpy(devsw, gt, sizeof *devsw);
596		cdevsw_free_devlocked(gt);
597		devsw->d_gianttrick = NULL;
598	}
599	devsw->d_flags &= ~D_INIT;
600}
601
602static int
603prep_cdevsw(struct cdevsw *devsw, int flags)
604{
605	struct cdevsw *dsw2;
606
607	mtx_assert(&devmtx, MA_OWNED);
608	if (devsw->d_flags & D_INIT)
609		return (0);
610	if (devsw->d_flags & D_NEEDGIANT) {
611		dev_unlock();
612		dsw2 = malloc(sizeof *dsw2, M_DEVT,
613		     (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
614		dev_lock();
615		if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
616			return (ENOMEM);
617	} else
618		dsw2 = NULL;
619	if (devsw->d_flags & D_INIT) {
620		if (dsw2 != NULL)
621			cdevsw_free_devlocked(dsw2);
622		return (0);
623	}
624
625	if (devsw->d_version != D_VERSION_03) {
626		printf(
627		    "WARNING: Device driver \"%s\" has wrong version %s\n",
628		    devsw->d_name == NULL ? "???" : devsw->d_name,
629		    "and is disabled.  Recompile KLD module.");
630		devsw->d_open = dead_open;
631		devsw->d_close = dead_close;
632		devsw->d_read = dead_read;
633		devsw->d_write = dead_write;
634		devsw->d_ioctl = dead_ioctl;
635		devsw->d_poll = dead_poll;
636		devsw->d_mmap = dead_mmap;
637		devsw->d_mmap_single = dead_mmap_single;
638		devsw->d_strategy = dead_strategy;
639		devsw->d_dump = dead_dump;
640		devsw->d_kqfilter = dead_kqfilter;
641	}
642
643	if (devsw->d_flags & D_NEEDGIANT) {
644		if (devsw->d_gianttrick == NULL) {
645			memcpy(dsw2, devsw, sizeof *dsw2);
646			devsw->d_gianttrick = dsw2;
647			dsw2 = NULL;
648		}
649	}
650
651#define FIXUP(member, noop, giant) 				\
652	do {							\
653		if (devsw->member == NULL) {			\
654			devsw->member = noop;			\
655		} else if (devsw->d_flags & D_NEEDGIANT)	\
656			devsw->member = giant;			\
657		}						\
658	while (0)
659
660	FIXUP(d_open,		null_open,	giant_open);
661	FIXUP(d_fdopen,		NULL,		giant_fdopen);
662	FIXUP(d_close,		null_close,	giant_close);
663	FIXUP(d_read,		no_read,	giant_read);
664	FIXUP(d_write,		no_write,	giant_write);
665	FIXUP(d_ioctl,		no_ioctl,	giant_ioctl);
666	FIXUP(d_poll,		no_poll,	giant_poll);
667	FIXUP(d_mmap,		no_mmap,	giant_mmap);
668	FIXUP(d_strategy,	no_strategy,	giant_strategy);
669	FIXUP(d_kqfilter,	no_kqfilter,	giant_kqfilter);
670	FIXUP(d_mmap_single,	no_mmap_single,	giant_mmap_single);
671
672	if (devsw->d_dump == NULL)	devsw->d_dump = no_dump;
673
674	LIST_INIT(&devsw->d_devs);
675
676	devsw->d_flags |= D_INIT;
677
678	if (dsw2 != NULL)
679		cdevsw_free_devlocked(dsw2);
680	return (0);
681}
682
683static int
684prep_devname(struct cdev *dev, const char *fmt, va_list ap)
685{
686	int len;
687	char *from, *q, *s, *to;
688
689	mtx_assert(&devmtx, MA_OWNED);
690
691	len = vsnrprintf(dev->__si_namebuf, sizeof(dev->__si_namebuf), 32,
692	    fmt, ap);
693	if (len > sizeof(dev->__si_namebuf) - 1)
694		return (ENAMETOOLONG);
695
696	/* Strip leading slashes. */
697	for (from = dev->__si_namebuf; *from == '/'; from++)
698		;
699
700	for (to = dev->__si_namebuf; *from != '\0'; from++, to++) {
701		/* Treat multiple sequential slashes as single. */
702		while (from[0] == '/' && from[1] == '/')
703			from++;
704		/* Trailing slash is considered invalid. */
705		if (from[0] == '/' && from[1] == '\0')
706			return (EINVAL);
707		*to = *from;
708	}
709	*to = '\0';
710
711	if (dev->__si_namebuf[0] == '\0')
712		return (EINVAL);
713
714	/* Disallow "." and ".." components. */
715	for (s = dev->__si_namebuf;;) {
716		for (q = s; *q != '/' && *q != '\0'; q++)
717			;
718		if (q - s == 1 && s[0] == '.')
719			return (EINVAL);
720		if (q - s == 2 && s[0] == '.' && s[1] == '.')
721			return (EINVAL);
722		if (*q != '/')
723			break;
724		s = q + 1;
725	}
726
727	if (devfs_dev_exists(dev->__si_namebuf) != 0)
728		return (EEXIST);
729
730	return (0);
731}
732
733static int
734make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
735    struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
736    va_list ap)
737{
738	struct cdev *dev, *dev_new;
739	int res;
740
741	KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
742	    ("make_dev_credv: both WAITOK and NOWAIT specified"));
743	dev_new = devfs_alloc(flags);
744	if (dev_new == NULL)
745		return (ENOMEM);
746	dev_lock();
747	res = prep_cdevsw(devsw, flags);
748	if (res != 0) {
749		dev_unlock();
750		devfs_free(dev_new);
751		return (res);
752	}
753	dev = newdev(devsw, unit, dev_new);
754	if ((dev->si_flags & SI_NAMED) == 0) {
755		res = prep_devname(dev, fmt, ap);
756		if (res != 0) {
757			if ((flags & MAKEDEV_CHECKNAME) == 0) {
758				panic(
759			"make_dev_credv: bad si_name (error=%d, si_name=%s)",
760				    res, dev->si_name);
761			}
762			if (dev == dev_new) {
763				LIST_REMOVE(dev, si_list);
764				dev_unlock();
765				devfs_free(dev);
766			} else
767				dev_unlock();
768			return (res);
769		}
770	}
771	if (flags & MAKEDEV_REF)
772		dev_refl(dev);
773	if (flags & MAKEDEV_ETERNAL)
774		dev->si_flags |= SI_ETERNAL;
775	if (dev->si_flags & SI_CHEAPCLONE &&
776	    dev->si_flags & SI_NAMED) {
777		/*
778		 * This is allowed as it removes races and generally
779		 * simplifies cloning devices.
780		 * XXX: still ??
781		 */
782		dev_unlock_and_free();
783		*dres = dev;
784		return (0);
785	}
786	KASSERT(!(dev->si_flags & SI_NAMED),
787	    ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
788	    devsw->d_name, dev2unit(dev), devtoname(dev)));
789	dev->si_flags |= SI_NAMED;
790	if (cr != NULL)
791		dev->si_cred = crhold(cr);
792	dev->si_uid = uid;
793	dev->si_gid = gid;
794	dev->si_mode = mode;
795
796	devfs_create(dev);
797	clean_unrhdrl(devfs_inos);
798	dev_unlock_and_free();
799
800	notify_create(dev, flags);
801
802	*dres = dev;
803	return (0);
804}
805
806struct cdev *
807make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
808    const char *fmt, ...)
809{
810	struct cdev *dev;
811	va_list ap;
812	int res;
813
814	va_start(ap, fmt);
815	res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
816	    ap);
817	va_end(ap);
818	KASSERT(res == 0 && dev != NULL,
819	    ("make_dev: failed make_dev_credv (error=%d)", res));
820	return (dev);
821}
822
823struct cdev *
824make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
825    gid_t gid, int mode, const char *fmt, ...)
826{
827	struct cdev *dev;
828	va_list ap;
829	int res;
830
831	va_start(ap, fmt);
832	res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
833	va_end(ap);
834
835	KASSERT(res == 0 && dev != NULL,
836	    ("make_dev_cred: failed make_dev_credv (error=%d)", res));
837	return (dev);
838}
839
840struct cdev *
841make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
842    uid_t uid, gid_t gid, int mode, const char *fmt, ...)
843{
844	struct cdev *dev;
845	va_list ap;
846	int res;
847
848	va_start(ap, fmt);
849	res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
850	    fmt, ap);
851	va_end(ap);
852
853	KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
854	    ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
855	    ("make_dev_credf: failed make_dev_credv (error=%d)", res));
856	return (res == 0 ? dev : NULL);
857}
858
859int
860make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
861    struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
862{
863	va_list ap;
864	int res;
865
866	va_start(ap, fmt);
867	res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
868	    fmt, ap);
869	va_end(ap);
870
871	KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
872	    ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
873	    ("make_dev_p: failed make_dev_credv (error=%d)", res));
874	return (res);
875}
876
877static void
878dev_dependsl(struct cdev *pdev, struct cdev *cdev)
879{
880
881	cdev->si_parent = pdev;
882	cdev->si_flags |= SI_CHILD;
883	LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
884}
885
886
887void
888dev_depends(struct cdev *pdev, struct cdev *cdev)
889{
890
891	dev_lock();
892	dev_dependsl(pdev, cdev);
893	dev_unlock();
894}
895
896static int
897make_dev_alias_v(int flags, struct cdev **cdev, struct cdev *pdev,
898    const char *fmt, va_list ap)
899{
900	struct cdev *dev;
901	int error;
902
903	KASSERT(pdev != NULL, ("make_dev_alias_v: pdev is NULL"));
904	KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
905	    ("make_dev_alias_v: both WAITOK and NOWAIT specified"));
906	KASSERT((flags & ~(MAKEDEV_WAITOK | MAKEDEV_NOWAIT |
907	    MAKEDEV_CHECKNAME)) == 0,
908	    ("make_dev_alias_v: invalid flags specified (flags=%02x)", flags));
909
910	dev = devfs_alloc(flags);
911	if (dev == NULL)
912		return (ENOMEM);
913	dev_lock();
914	dev->si_flags |= SI_ALIAS;
915	error = prep_devname(dev, fmt, ap);
916	if (error != 0) {
917		if ((flags & MAKEDEV_CHECKNAME) == 0) {
918			panic("make_dev_alias_v: bad si_name "
919			    "(error=%d, si_name=%s)", error, dev->si_name);
920		}
921		dev_unlock();
922		devfs_free(dev);
923		return (error);
924	}
925	dev->si_flags |= SI_NAMED;
926	devfs_create(dev);
927	dev_dependsl(pdev, dev);
928	clean_unrhdrl(devfs_inos);
929	dev_unlock();
930
931	notify_create(dev, flags);
932	*cdev = dev;
933
934	return (0);
935}
936
937struct cdev *
938make_dev_alias(struct cdev *pdev, const char *fmt, ...)
939{
940	struct cdev *dev;
941	va_list ap;
942	int res;
943
944	va_start(ap, fmt);
945	res = make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap);
946	va_end(ap);
947
948	KASSERT(res == 0 && dev != NULL,
949	    ("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
950	return (dev);
951}
952
953int
954make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
955    const char *fmt, ...)
956{
957	va_list ap;
958	int res;
959
960	va_start(ap, fmt);
961	res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
962	va_end(ap);
963	return (res);
964}
965
966int
967make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev,
968    struct cdev *old_alias, const char *physpath)
969{
970	char *devfspath;
971	int physpath_len;
972	int max_parentpath_len;
973	int parentpath_len;
974	int devfspathbuf_len;
975	int mflags;
976	int ret;
977
978	*cdev = NULL;
979	devfspath = NULL;
980	physpath_len = strlen(physpath);
981	ret = EINVAL;
982	if (physpath_len == 0)
983		goto out;
984
985	if (strncmp("id1,", physpath, 4) == 0) {
986		physpath += 4;
987		physpath_len -= 4;
988		if (physpath_len == 0)
989			goto out;
990	}
991
992	max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
993	parentpath_len = strlen(pdev->si_name);
994	if (max_parentpath_len < parentpath_len) {
995		if (bootverbose)
996			printf("WARNING: Unable to alias %s "
997			    "to %s/%s - path too long\n",
998			    pdev->si_name, physpath, pdev->si_name);
999		ret = ENAMETOOLONG;
1000		goto out;
1001	}
1002
1003	mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
1004	devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
1005	devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
1006	if (devfspath == NULL) {
1007		ret = ENOMEM;
1008		goto out;
1009	}
1010
1011	sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
1012	if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
1013		/* Retain the existing alias. */
1014		*cdev = old_alias;
1015		old_alias = NULL;
1016		ret = 0;
1017	} else {
1018		ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
1019	}
1020out:
1021	if (old_alias != NULL)
1022		destroy_dev(old_alias);
1023	if (devfspath != NULL)
1024		free(devfspath, M_DEVBUF);
1025	return (ret);
1026}
1027
1028static void
1029destroy_devl(struct cdev *dev)
1030{
1031	struct cdevsw *csw;
1032	struct cdev_privdata *p;
1033
1034	mtx_assert(&devmtx, MA_OWNED);
1035	KASSERT(dev->si_flags & SI_NAMED,
1036	    ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
1037	KASSERT((dev->si_flags & SI_ETERNAL) == 0,
1038	    ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
1039	     dev2unit(dev)));
1040
1041	devfs_destroy(dev);
1042
1043	/* Remove name marking */
1044	dev->si_flags &= ~SI_NAMED;
1045
1046	dev->si_refcount++;	/* Avoid race with dev_rel() */
1047
1048	/* If we are a child, remove us from the parents list */
1049	if (dev->si_flags & SI_CHILD) {
1050		LIST_REMOVE(dev, si_siblings);
1051		dev->si_flags &= ~SI_CHILD;
1052	}
1053
1054	/* Kill our children */
1055	while (!LIST_EMPTY(&dev->si_children))
1056		destroy_devl(LIST_FIRST(&dev->si_children));
1057
1058	/* Remove from clone list */
1059	if (dev->si_flags & SI_CLONELIST) {
1060		LIST_REMOVE(dev, si_clone);
1061		dev->si_flags &= ~SI_CLONELIST;
1062	}
1063
1064	csw = dev->si_devsw;
1065	dev->si_devsw = NULL;	/* already NULL for SI_ALIAS */
1066	while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
1067		csw->d_purge(dev);
1068		msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
1069		if (dev->si_threadcount)
1070			printf("Still %lu threads in %s\n",
1071			    dev->si_threadcount, devtoname(dev));
1072	}
1073	while (dev->si_threadcount != 0) {
1074		/* Use unique dummy wait ident */
1075		msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
1076	}
1077
1078	dev_unlock();
1079	notify_destroy(dev);
1080	mtx_lock(&cdevpriv_mtx);
1081	while ((p = LIST_FIRST(&cdev2priv(dev)->cdp_fdpriv)) != NULL) {
1082		devfs_destroy_cdevpriv(p);
1083		mtx_lock(&cdevpriv_mtx);
1084	}
1085	mtx_unlock(&cdevpriv_mtx);
1086	dev_lock();
1087
1088	dev->si_drv1 = 0;
1089	dev->si_drv2 = 0;
1090	bzero(&dev->__si_u, sizeof(dev->__si_u));
1091
1092	if (!(dev->si_flags & SI_ALIAS)) {
1093		/* Remove from cdevsw list */
1094		LIST_REMOVE(dev, si_list);
1095
1096		/* If cdevsw has no more struct cdev *'s, clean it */
1097		if (LIST_EMPTY(&csw->d_devs)) {
1098			fini_cdevsw(csw);
1099			wakeup(&csw->d_devs);
1100		}
1101	}
1102	dev->si_flags &= ~SI_ALIAS;
1103	dev->si_refcount--;	/* Avoid race with dev_rel() */
1104
1105	if (dev->si_refcount > 0) {
1106		LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
1107	} else {
1108		dev_free_devlocked(dev);
1109	}
1110}
1111
1112void
1113destroy_dev(struct cdev *dev)
1114{
1115
1116	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
1117	dev_lock();
1118	destroy_devl(dev);
1119	dev_unlock_and_free();
1120}
1121
1122const char *
1123devtoname(struct cdev *dev)
1124{
1125
1126	return (dev->si_name);
1127}
1128
1129int
1130dev_stdclone(char *name, char **namep, const char *stem, int *unit)
1131{
1132	int u, i;
1133
1134	i = strlen(stem);
1135	if (bcmp(stem, name, i) != 0)
1136		return (0);
1137	if (!isdigit(name[i]))
1138		return (0);
1139	u = 0;
1140	if (name[i] == '0' && isdigit(name[i+1]))
1141		return (0);
1142	while (isdigit(name[i])) {
1143		u *= 10;
1144		u += name[i++] - '0';
1145	}
1146	if (u > 0xffffff)
1147		return (0);
1148	*unit = u;
1149	if (namep)
1150		*namep = &name[i];
1151	if (name[i])
1152		return (2);
1153	return (1);
1154}
1155
1156/*
1157 * Helper functions for cloning device drivers.
1158 *
1159 * The objective here is to make it unnecessary for the device drivers to
1160 * use rman or similar to manage their unit number space.  Due to the way
1161 * we do "on-demand" devices, using rman or other "private" methods
1162 * will be very tricky to lock down properly once we lock down this file.
1163 *
1164 * Instead we give the drivers these routines which puts the struct cdev *'s
1165 * that are to be managed on their own list, and gives the driver the ability
1166 * to ask for the first free unit number or a given specified unit number.
1167 *
1168 * In addition these routines support paired devices (pty, nmdm and similar)
1169 * by respecting a number of "flag" bits in the minor number.
1170 *
1171 */
1172
1173struct clonedevs {
1174	LIST_HEAD(,cdev)	head;
1175};
1176
1177void
1178clone_setup(struct clonedevs **cdp)
1179{
1180
1181	*cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1182	LIST_INIT(&(*cdp)->head);
1183}
1184
1185int
1186clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1187    struct cdev **dp, int extra)
1188{
1189	struct clonedevs *cd;
1190	struct cdev *dev, *ndev, *dl, *de;
1191	int unit, low, u;
1192
1193	KASSERT(*cdp != NULL,
1194	    ("clone_setup() not called in driver \"%s\"", csw->d_name));
1195	KASSERT(!(extra & CLONE_UNITMASK),
1196	    ("Illegal extra bits (0x%x) in clone_create", extra));
1197	KASSERT(*up <= CLONE_UNITMASK,
1198	    ("Too high unit (0x%x) in clone_create", *up));
1199	KASSERT(csw->d_flags & D_NEEDMINOR,
1200	    ("clone_create() on cdevsw without minor numbers"));
1201
1202
1203	/*
1204	 * Search the list for a lot of things in one go:
1205	 *   A preexisting match is returned immediately.
1206	 *   The lowest free unit number if we are passed -1, and the place
1207	 *	 in the list where we should insert that new element.
1208	 *   The place to insert a specified unit number, if applicable
1209	 *       the end of the list.
1210	 */
1211	unit = *up;
1212	ndev = devfs_alloc(MAKEDEV_WAITOK);
1213	dev_lock();
1214	prep_cdevsw(csw, MAKEDEV_WAITOK);
1215	low = extra;
1216	de = dl = NULL;
1217	cd = *cdp;
1218	LIST_FOREACH(dev, &cd->head, si_clone) {
1219		KASSERT(dev->si_flags & SI_CLONELIST,
1220		    ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1221		u = dev2unit(dev);
1222		if (u == (unit | extra)) {
1223			*dp = dev;
1224			dev_unlock();
1225			devfs_free(ndev);
1226			return (0);
1227		}
1228		if (unit == -1 && u == low) {
1229			low++;
1230			de = dev;
1231			continue;
1232		} else if (u < (unit | extra)) {
1233			de = dev;
1234			continue;
1235		} else if (u > (unit | extra)) {
1236			dl = dev;
1237			break;
1238		}
1239	}
1240	if (unit == -1)
1241		unit = low & CLONE_UNITMASK;
1242	dev = newdev(csw, unit | extra, ndev);
1243	if (dev->si_flags & SI_CLONELIST) {
1244		printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1245		printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1246		LIST_FOREACH(dev, &cd->head, si_clone) {
1247			printf("\t%p %s\n", dev, dev->si_name);
1248		}
1249		panic("foo");
1250	}
1251	KASSERT(!(dev->si_flags & SI_CLONELIST),
1252	    ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1253	if (dl != NULL)
1254		LIST_INSERT_BEFORE(dl, dev, si_clone);
1255	else if (de != NULL)
1256		LIST_INSERT_AFTER(de, dev, si_clone);
1257	else
1258		LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1259	dev->si_flags |= SI_CLONELIST;
1260	*up = unit;
1261	dev_unlock_and_free();
1262	return (1);
1263}
1264
1265/*
1266 * Kill everything still on the list.  The driver should already have
1267 * disposed of any softc hung of the struct cdev *'s at this time.
1268 */
1269void
1270clone_cleanup(struct clonedevs **cdp)
1271{
1272	struct cdev *dev;
1273	struct cdev_priv *cp;
1274	struct clonedevs *cd;
1275
1276	cd = *cdp;
1277	if (cd == NULL)
1278		return;
1279	dev_lock();
1280	while (!LIST_EMPTY(&cd->head)) {
1281		dev = LIST_FIRST(&cd->head);
1282		LIST_REMOVE(dev, si_clone);
1283		KASSERT(dev->si_flags & SI_CLONELIST,
1284		    ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1285		dev->si_flags &= ~SI_CLONELIST;
1286		cp = cdev2priv(dev);
1287		if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1288			cp->cdp_flags |= CDP_SCHED_DTR;
1289			KASSERT(dev->si_flags & SI_NAMED,
1290				("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
1291			destroy_devl(dev);
1292		}
1293	}
1294	dev_unlock_and_free();
1295	free(cd, M_DEVBUF);
1296	*cdp = NULL;
1297}
1298
1299static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1300	TAILQ_HEAD_INITIALIZER(dev_ddtr);
1301static struct task dev_dtr_task;
1302
1303static void
1304destroy_dev_tq(void *ctx, int pending)
1305{
1306	struct cdev_priv *cp;
1307	struct cdev *dev;
1308	void (*cb)(void *);
1309	void *cb_arg;
1310
1311	dev_lock();
1312	while (!TAILQ_EMPTY(&dev_ddtr)) {
1313		cp = TAILQ_FIRST(&dev_ddtr);
1314		dev = &cp->cdp_c;
1315		KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1316		    ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1317		TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1318		cb = cp->cdp_dtr_cb;
1319		cb_arg = cp->cdp_dtr_cb_arg;
1320		destroy_devl(dev);
1321		dev_unlock_and_free();
1322		dev_rel(dev);
1323		if (cb != NULL)
1324			cb(cb_arg);
1325		dev_lock();
1326	}
1327	dev_unlock();
1328}
1329
1330/*
1331 * devmtx shall be locked on entry. devmtx will be unlocked after
1332 * function return.
1333 */
1334static int
1335destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1336{
1337	struct cdev_priv *cp;
1338
1339	mtx_assert(&devmtx, MA_OWNED);
1340	cp = cdev2priv(dev);
1341	if (cp->cdp_flags & CDP_SCHED_DTR) {
1342		dev_unlock();
1343		return (0);
1344	}
1345	dev_refl(dev);
1346	cp->cdp_flags |= CDP_SCHED_DTR;
1347	cp->cdp_dtr_cb = cb;
1348	cp->cdp_dtr_cb_arg = arg;
1349	TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1350	dev_unlock();
1351	taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1352	return (1);
1353}
1354
1355int
1356destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1357{
1358
1359	dev_lock();
1360	return (destroy_dev_sched_cbl(dev, cb, arg));
1361}
1362
1363int
1364destroy_dev_sched(struct cdev *dev)
1365{
1366
1367	return (destroy_dev_sched_cb(dev, NULL, NULL));
1368}
1369
1370void
1371destroy_dev_drain(struct cdevsw *csw)
1372{
1373
1374	dev_lock();
1375	while (!LIST_EMPTY(&csw->d_devs)) {
1376		msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1377	}
1378	dev_unlock();
1379}
1380
1381void
1382drain_dev_clone_events(void)
1383{
1384
1385	sx_xlock(&clone_drain_lock);
1386	sx_xunlock(&clone_drain_lock);
1387}
1388
1389static void
1390devdtr_init(void *dummy __unused)
1391{
1392
1393	TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL);
1394}
1395
1396SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
1397
1398#include "opt_ddb.h"
1399#ifdef DDB
1400#include <sys/kernel.h>
1401
1402#include <ddb/ddb.h>
1403
1404DB_SHOW_COMMAND(cdev, db_show_cdev)
1405{
1406	struct cdev_priv *cdp;
1407	struct cdev *dev;
1408	u_int flags;
1409	char buf[512];
1410
1411	if (!have_addr) {
1412		TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1413			dev = &cdp->cdp_c;
1414			db_printf("%s %p\n", dev->si_name, dev);
1415			if (db_pager_quit)
1416				break;
1417		}
1418		return;
1419	}
1420
1421	dev = (struct cdev *)addr;
1422	cdp = cdev2priv(dev);
1423	db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1424	    dev->si_name, dev->si_refcount, dev->si_usecount,
1425	    dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1426	db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1427	    dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1428	flags = dev->si_flags;
1429#define	SI_FLAG(flag)	do {						\
1430	if (flags & (flag)) {						\
1431		if (buf[0] != '\0')					\
1432			strlcat(buf, ", ", sizeof(buf));		\
1433		strlcat(buf, (#flag) + 3, sizeof(buf));			\
1434		flags &= ~(flag);					\
1435	}								\
1436} while (0)
1437	buf[0] = '\0';
1438	SI_FLAG(SI_ETERNAL);
1439	SI_FLAG(SI_ALIAS);
1440	SI_FLAG(SI_NAMED);
1441	SI_FLAG(SI_CHEAPCLONE);
1442	SI_FLAG(SI_CHILD);
1443	SI_FLAG(SI_DEVOPEN);
1444	SI_FLAG(SI_CONSOPEN);
1445	SI_FLAG(SI_DUMPDEV);
1446	SI_FLAG(SI_CANDELETE);
1447	SI_FLAG(SI_CLONELIST);
1448	db_printf("si_flags %s\n", buf);
1449
1450	flags = cdp->cdp_flags;
1451#define	CDP_FLAG(flag)	do {						\
1452	if (flags & (flag)) {						\
1453		if (buf[0] != '\0')					\
1454			strlcat(buf, ", ", sizeof(buf));		\
1455		strlcat(buf, (#flag) + 4, sizeof(buf));			\
1456		flags &= ~(flag);					\
1457	}								\
1458} while (0)
1459	buf[0] = '\0';
1460	CDP_FLAG(CDP_ACTIVE);
1461	CDP_FLAG(CDP_SCHED_DTR);
1462	db_printf("cdp_flags %s\n", buf);
1463}
1464#endif
1465